With Sulvo's Fluid ad units it is possible that an ad is sold that is smaller than the available space in the ad unit container. This can occur because the ad server always finds and sells the ad unit with the highest bid for that visitor, even if that ad unit is smaller than the available container. Please see the related articles for how to best manage this behavior for your site.
If the Sulvo ad server does serve a smaller ad unit than the available container space the following will occur based on the ad unit placement. This behavior has been optimized based on millions of impressions to achieve the best visitor UX, SEO results, and ad revenue.
Above the fold (ATF) ad units:
If an ad unit is ATF any white space will not be removed. Removing whitespace ATF cause the entire page to reflow, possibly moving text and content as the page loads. This results in a bad visitor UX and can negatively affect earnings.
Below the fold (BTF) ad units:
If an ad unit is BTF any white space will be removed. Removing whitespace BTF cause only the page BTF to reflow, possibly moving text and content that is not in view. This does not affect visitor UX until they scroll BTF so it does not negatively affect earnings.